More About the PAM00687 Special Edition:In the late 1930s, Panerai made a number of Radiomir watches with a special 12-sided bezel, engraved with the words “OFFICINE PANERAI – BREVETTATO”. This inscription referred to the patented luminous substance Radiomir used on the dial, and it suggests that the watches were used not for military operations but for presenting to the authorities of the Royal Italian Navy, which was evaluating new instruments for underwater missions. The Special Edition Radiomir 3 Days Acciaio reproduces all the fundamental characteristics of these vintage watches, respecting their identity and giving collectors the opportunity to appreciate a fascinating chapter in the Panerai story.